Inverter-Integrated Electric Compressor

ABSTRACT

Provided is an inverter-integrated electric compressor whose inverter section is molded using a urethane resin and which is excellent in joining reliability of electrically connected section. An inverter-integrated electric compressor, wherein the compressor incorporates a motor and wherein a motor drive circuit including the inverter is provided in a containing space surrounded by a compressor housing. A crimping section of a terminal of a conducting wire connected to the inverter is molded, together with the inverter, in a resin charged into the containing space. A gap at the crimping section, the gap being open to the outside, is previously covered and sealed by a gap sealant.

TECHNICAL FIELD OF THE INVENTION

The present invention relates to an inverter-integrated electriccompressor in which a motor drive circuit including an inverter isassembled, and specifically, relates to an inverter-integrated electriccompressor in which the inverter portion is molded by urethane resin,etc.

BACKGROUND ART OF THE INVENTION

As a structure of an inverter-integrated electric compressor in which amotor drive circuit including an inverter is assembled, a structure isknown wherein a motor drive circuit is coated by a resin mold materialfor insulation so as to be buried in the resin mold material (e.g.Patent document 1). A lead wire for inputting high voltage to theinverter portion in such a compressor, for example, is connected to theinverter portion by being connected by a screw to a circuit board forthe inverter portion through a connector for high voltage (an HVconnector) comprising a solderless terminal.

PRIOR ART DOCUMENTS Patent Documents

-   Patent document 1: JP-A-2002-70743

SUMMARY OF THE INVENTION Problems to be Solved by the Invention

In an inverter-integrated electric compressor shown in Patent document1, a space for housing a motor drive circuit is filled with a moldmaterial such as urethane resin, etc. in order to protect partsconstituting the inverter portion, etc. from heat and vibration.However, if the mold material flows in a gap around a conducting wire ata crimping section of the HV connector during the filling operation,because the mold material repeats expansion and contraction caused by atemperature variation of the HV connector accompanied with fluctuationof the operation condition of the compressor, there is a fear that aconnection reliability of the crimping section of the HV connector mayreduce.

Accordingly, an object of the present invention is to provide aninverter-integrated electric compressor in which an inverter portion ismolded by urethane resin, etc. and which is excellent in joiningreliability of electrically connected section.

Means for Solving the Problems

To achieve the above-described object, an inverter-integrated electriccompressor according to the present invention has a built-in motor andis provided with a motor drive circuit including an inverter which isinstalled in a containing space surrounded by a compressor housing, andis characterized in that a crimping section of a terminal of aconducting wire connected to the inverter is molded, together with theinverter, in a resin charged into the containing space, and a gap opento the outside at the crimping section is previously covered and sealedby a gap sealant.

In the inverter-integrated electric compressor according to the presentinvention, because the crimping section is molded together with theinverter at a condition where a gap open to the outside at the crimpingsection of the terminal of the lead wire connected to the inverter iscovered and sealed by a gap sealant, the mold material is prevented fromflowing in an inner gap of the crimping section and therefore thejoining reliability of the crimping section is secured. As theabove-described gap sealant, it is preferred to use a material whosedegree of an expansion or contraction caused by a temperature variationof an HV connector is small. By using such a material, it becomespossible to secure a sufficient connection reliability of theabove-described crimping section.

Further, in order to cover and seal the inside of the above-describedopen gap efficiently by using the above-described gap sealant, as forthe gap sealant, it is preferred to use a material which can exhibit afluidized state temporarily by heating, etc. and can be solidified bycooling, etc. Concretely, a gap sealant consisting of solder can bepreferably used. For example, by making a condition where a solder isfluidized temporarily by a heated soldering iron, and at that condition,by charging the solder into the open gap, and by solidifying the solderby natural or forcible cooling, the covering and sealing of the gap opento the outside at the crimping section can be performed efficiently.

Further, in the present invention, even though the inside of the opengap is covered and sealed, if a cross-sectional portion of a tip of theconducting wire is exposed, there is a fear that a mold materialadhering to an irregularity part of the cross-sectional portion of thetip repeats expansion and contraction, whereby a stress may be appliedto the tip of the conducting wire and the joining reliability of thecrimping section may reduce. Therefore, it is preferred that thecross-sectional portion of the tip of the conducting wire is covered bythe gap sealant so that the irregularity part of the cross-sectionalportion of the tip of the conducting wire is smothered thereby.

The inverter-integrated electric compressor according to the presentinvention can be applied to substantially any types of compressors, andin particular, it can be suitably used as a compressor mounted on avehicle, which is often installed in a narrow space and its motor drivecircuit of which is liable to be affected by heat and vibration.

Effect According to the Invention

In the inverter-integrated electric compressor according to the presentinvention, because the containing space surrounded by the compressorhousing is molded, together with the inverter, under a condition wherethe gap open to the outside at the crimping section of the terminal ofthe conducting wire connected to the inverter is previously covered andsealed by the gap sealant, the mold material is prevented from flowinginto the crimping section of the terminal of the conducting wireconnected to the inverter, and therefore it is possible to secure theconnection stability and connection reliability of the crimping section.

BRIEF EXPLANATION OF THE DRAWINGS

FIG. 1 is a schematic vertical cross-sectional view showing a basicconfiguration of an inverter-integrated electric compressor according toan embodiment of the present invention.

FIG. 2 is a diagram of a configuration showing a control mechanism ofair conditioning system including the compressor depicted in FIG. 1 fromthe viewpoint of electric circuit.

FIG. 3 is a perspective view showing a state where a motor drive circuitis installed in a containing space surrounded by a front housingdepicted in FIG. 1.

FIG. 4 depicts a crimping section connecting an HV connector and a leadwire depicted in FIG. 3, where (A) is a perspective view showing anuncovered state of the section and (B) is a perspective view showing acovered state of the section.

EMBODIMENTS FOR CARRYING OUT THE INVENTION

Hereinafter, desirable embodiments of the present invention will beexplained referring to figures.

FIG. 1 shows an example of a scroll type inverter-integrated electriccompressor for automotive air conditioning system as a basicconfiguration of an inverter-integrated electric compressor 1 accordingto an embodiment of the present invention. In FIG. 1, symbol 2 shows acompression mechanism comprising a fixed scroll 3 and a movable scroll4. Movable scroll 4 is moved orbitally relative to fixed scroll 3 at acondition where the rotation is prevented via ball coupling 5. Motor 7is incorporated into compressor housing 6 (center housing), and mainshaft 8 (rotation axis) is driven to be rotated by the built-in motor 7.Rotational movement of main shaft 8 is transformed to an orbitalmovement of movable scroll 4, through eccentric pin 9 provided at oneend of main shaft 8 and eccentric bush 10 which is engaged rotatablywith it. In this embodiment, suction port 11 sucking a refrigerant as afluid to be compressed is provided in compressor housing 12 (fronthousing), and the sucked refrigerant is led to compression mechanism 2through a section placed with motor 7, and the refrigerant which hasbeen compressed by compression mechanism 2 is delivered to an externalcircuit through discharge hole 13, discharge chamber 14, and dischargeport 16 which is provided in compressor housing 15 (rear housing).

Motor drive circuit 21 for motor 7 is provided in compressor housing 12(front housing), and in more detail, motor drive circuit 21 is providedat the outer surface side of partition wall 22 which is formed incompressor housing 12 for separating from the side of the refrigerantsuction route. Motor drive circuit 21 supplies electric power to motor 7via sealed terminal 23 (output terminal of motor drive circuit 21)attached through partition wall 22, and lead wire 24, and the side ofrefrigerant suction route and the side of a section placing motor drivecircuit 21 are sealed from each other at a section placing sealedterminal 23. By providing motor drive circuit 21 at the outer surfaceside of partition wall 22, at least a part of electric parts includingmotor drive circuit 21 can exchange heat through partition wall 22 withsucked refrigerant, so as to be cooled by the sucked refrigerant.

Motor drive circuit 21 includes IPM 25 (intelligent Power Module) havingan inverter function and control circuit 26, and is provided withelectric parts such as capacitor 27, etc. separately therefrom orintegrally therewith. This motor drive circuit 21 is connected to anexternal power supply (not shown) through connector 28 as an inputterminal. The side open to the outside of compressor housing 12, inwhich electric parts including motor drive circuit 21 are mounted, iscovered by lid member 29 at a sealed condition, and these electric partsare protected by the lid member 29.

From the viewpoint of electric circuit, the above-describedconfiguration can be depicted as shown in FIG. 2, for example. In FIG.2, electric compressor 1 is provided with motor drive circuit 21, and bysupplying an output of motor drive circuit 21 to respective motor coils47 of built-in motor 7 through sealed terminal 23 and lead wire 24,motor 7 is rotationally driven, and compression by compression mechanism2 is performed. Motor drive circuit 21 has high voltage circuit fordriving motor 30, and low voltage circuit for control 45 which isprovided with motor control circuit 44 for controlling respective powerelements 43 (switching elements) of inverter 42 in high voltage circuitfor driving motor 30, and this low voltage circuit for control 45 isconfigured in control circuit 26 shown in FIG. 1. Power from externalpower source 46 (for example, a battery) is supplied to high voltagecircuit for driving motor 30 through high voltage connector 47 and issupplied to inverter 42 through noise filter 37 and capacitor forsmoothing 27, and after the DC from power source 46 is converted topseudo three-phase AC by inverter 42, the power is supplied to motor 7.Motor control circuit 44 is supplied with low voltage power, forexample, from air conditioning control unit for vehicles 48 throughconnector for control signal 49. Although this connector for controlsignal 49 and connector for high voltage 47 are depicted in FIG. 2 atpositions separate from each other, both of the connectors are actuallyinstalled inside the same connector 28 shown in FIG. 1. Shield plate 31is fixed to control circuit 26 and, as shown in FIG. 2, this shieldplate 31 is interposed between high voltage circuit for driving motors30 and control circuit 26 provided with low voltage circuit for control45, covering high voltage circuit for driving motor 30 over an area asbroad as possible so as to suppress an influence of noise from the sideof high voltage circuit for driving motor 30 to the side of low voltagecircuit for control 45.

FIG. 3 is a perspective view showing motor drive circuit 21 beinglocated in containing space 60 surrounded by compressor housing 12(front housing). Case member 58 and IPM 25 are stored in containingspace 60. Further, connector for high voltage 47 consisting of asolderless terminal is connected to the tip of lead wire 24 by beingcrimped. Connector for high voltage 47 is fixed by a screw to casemember 58 and is connected electrically between capacitor 27 and noisefilter 37 which are mounted on the back surface of case member 58.

FIG. 4 depicts a crimping section joining connector for high voltage 47to lead wire 24 shown in FIG. 3, where (A) is a perspective viewdepicting a state where the crimping section is not covered, and (B) isa perspective view depicting a state where the crimping section iscovered with solder. In FIG. 4 (A), connector for high voltage 47 isconnected to lead wire 24 by being crimped. In crimping section 61, aplurality of conducting wires bundled by a cover of lead wire 24 forms agap open to the outside 63, and if a mold material consisting ofurethane resin, etc. enters into this open gap 63, the connectionreliability of crimping section 61 will reduce. Therefore, as shown inFIG. 4 (B), by molding containing space 60 together with inverter 42 byflowing solder 64 as a gap sealant into open gap 63, and charging themold material into containing space 60 shown in FIG. 3, the moldmaterial can be prevented from flowing into crimping section 61. Inparticular, as shown in FIG. 4 (B), by covering the cross-sectionalportion of the tip of conducting wire 62 with solder 64 completely, itis possible to secure the connection reliability of crimping section 61sufficiently even when the mold material adheres to this portion.

INDUSTRIAL APPLICATIONS OF THE INVENTION

The inverter-integrated electric compressor according to the presentinvention can be applied substantially to all types of compressors, andis specifically suitable for a compressor mounted on a vehicle, which isoften installed in a narrow space and is provided with a motor drivecircuit that is liable to be affected by heat and vibration.

EXPLANATION OF SYMBOLS

-   1: inverter-integrated electric compressor-   2: compression mechanism-   3: fixed scroll-   4: movable scroll-   5: ball coupling-   6: compressor housing (center housing)-   7: motor-   8: main shaft-   9: eccentric pin-   10: eccentric bush-   11: suction port-   12: compressor housing (front housing)-   13: discharge hole-   14: discharge chamber-   15: compressor housing (rear housing)-   16: discharge port-   21: motor drive circuit-   22: partition wall-   23: sealed terminal-   24: lead wire-   25: IPM-   26: control circuit-   27: capacitor-   28: connector-   29: lid member-   30: high voltage circuit for driving motor-   31: shield plate-   37: noise filter-   41: motor coil-   42: inverter-   43: power element-   44: motor control circuit-   45: low voltage circuit for control-   46: external power supply-   47: connector for high voltage (HV connector)-   48: air conditioning control unit-   49: connector for control signal-   58: case member-   60: containing space-   61: crimping section-   62: conducting wire-   63: open gap-   64: solder as a gap sealant

1. An inverter-integrated electric compressor having a built-in motorand provided with a motor drive circuit including an inverter which isinstalled in a containing space surrounded by a compressor housing,wherein a crimping section of a terminal of a conducting wire connectedto said inverter is molded, together with said inverter, in a resincharged into said containing space, and a gap open to the outside atsaid crimping section is previously covered and sealed by a gap sealant.2. The inverter-integrated electric compressor according to claim 1,wherein a cross-sectional portion of a tip of said conducting wire iscovered by said gap sealant.
 3. The inverter-integrated electriccompressor according to claim 1, wherein said gap sealant consists of asolder.
 4. The inverter-integrated electric compressor according toclaim 1, wherein said inverter-integrated electric compressor is acompressor mounted on a vehicle.